1. Field of Invention
The present invention relates to a method of fabricating a memory structure. More particularly, the present invention relates to a method of fabricating a non-volatile memory structure.
2. Description of Related Art
Flash memory in a non-volatile memory has become one of the research mainstreams in the field due to its fast and time-saving operating mode and lower cost advantage. A typical flash memory device is mainly constituted by a floating gate and a control gate. The control gate is directly disposed on the floating gate and is isolated from the floating gate by a dielectric layer, while the floating gate and the substrate are isolated by a tunneling oxide layer.
At present, flash memory arrays commonly used in the field include a NOR-type array structure type and a NAND-type array structure type. In the NAND-type array flash memory structure, various memory cells are connected in series so as to provide a superior integrated density and area utilization compared with the NOR-type array flash memory, and it has been widely used in various electronic products.
However, as for the NAND-type array flash memory structure, when forming a contact window connected to the source/drain region, short circuits of the contact window or the outmost select gate in the memory cell row often occur, thereby reducing the product yield.